Antiweld and antiwear lubricating oil composition



Patented June 7, 1960 halogenated phosphite ester used, but in generalshould not exceed about five times by weight the amount of free I2,939,843 sulfur present in the oil. For example, if the oil contains02% of free sulfur, the phosphite should not ex- ANTIWELD WE fi 5 ceedabout 1% by weight of the oil composition. a In preparing lubricatingoils in accordance with our John N. Bowden and Paul R. Chapman, CrystalLake, invention, a mineral lubricating oil of desired viscosity 11].,assignors to The Pure Oil Company, g and other properties is blendedwith about 0.5 to 5% of wrpol'atloll of 01110 lead naphthenate and 0.05to 1% of sulfur. An oil of this compositionhas excellent load-carryingcharacteris- No Drawing' Filed 1956 605,697 ties as indicated by thefour-ball weld test, but has a poor 4Claims. ((1252-5873)wear-preventive characteristics as demonstrated by the four-ball,5-minute wear test. The four-ball test for determining load-carrying andwear properties is briefly deinvention relates to lubricating oils andmore scribed on pages 13 and 14 of The Performance of particularlytolubricating oils capable of withstanding Lubricating Oils, by 'Zuideman,published in 1952 by high loads. Reinhold Publishing Corp., New York. Toimprove the It. is common practice to incorporate into mineral lubriwearcharacteristics of this oil, a small amount of a eating oils intendedfor lubricating automotive gears and halogenated phosphite ester of theorder of 0.1 to 5% by other mechanical parts subject to extremepressures, adweight is incorporated in the oil. As examples ofhaloditives which are capable of enhancing the load-carrying genatedphosphite esters which may be used are tri(chloproperties of the oil.Among the additives commonly roethyl) phosphite, chlorooctyl dihydrogenphosphite, used for this purpose, particularly in break-in oils ordi(chlorooctyl) hydrogen phosphite, tri(bromopropyl) oils intended forlubricating green gears, are lead phosphite, tri(bromohexyl) phosphite,di(bron1oheptyl) naphthenate and free sulfur. Lead naphthenate and freehydrogen phosphite, tri(chlorooctyl) phosphite, tri(chlosulfur, however,have the drawbrack of causing high robutyl) phosphite, tri(chloroamyl)phosphite, and triwear under low speed-high torque conditions. In other(chlorolauryl) phosphite. The partial esters may be so words, althoughthe combination of lead naphthenate strongly acidic as to be corrosiveto the metal, in which and sulfur impart satisfactory anti-weldcharacteristics case either the quantity of the partial ester in theblend to the oil; it is not a satisfactory E.P. additive combinacan bereduced, or the blend can be treated withbasic tion under the variedconditions encountered in service. oxides or hydroxides, such as thoseof calcium, barium, We have discovered that if a small amount of ahalozinc, lead, etc., or with basic nitrogen compounds, such alkylphosphite is incorporated into the oil containing as ammonia and amines,in order to eliminate corrosivity. sulfur, with or without leadnaphthenate, the anti-wear Haloalkyl phosphites containing from 1 to 30carbon properties of the oil are materially improved while the atoms inthe alkyl radicals are satisfactory, as long as anti-weld properties ofthe oil remain at a high level. the compounds are substantiallynon-volatile under'serv- An object of our invention is to provide a newlubriice conditions and are sufliciently soluble in the oil so catingoil composition. Another object of our invention that they remain insolution and will not precipitate out is to provide an extreme pressuregear oil which is satisduring Storage 1' in Se icefactory both underhigh speed-low torque and low speed- 40 In order to illustrate theinvention, a number of blends high torque operating conditions. A stillfurther object were prepared by mixing with mineral lubricating oil, ofthe invention is to provide a lubricant having good lead naphthenate,sulfur and several different phosphorus anti-wear and anti-weldproperties. Other objects of the compounds until a homogeneous solutionwas obtained. invention will manifest themselves from the followingBlends were tested on the four-ball machine. The results description. ofthe tests are given in the following table.

Table I Blend Number Composition, parts by weight 1 2 3 4 0 6 7 8 Leadnaphthenate 4. 0 4. 00 4. 0 4. 0' 4. 0 Sulfur l 0. 2 0.08 0. 1 o. 1 0. 1ErKchloroethyDphosphite.. 1.0 1 00 xtract-PgS reaction product.-. 1.0Dicetyl dithiophosphorie acid 1. 0 Zinc salt of extract-P 8; reactionproduct 1. Mineral oil 94. 8 s4. 92 94. 9 94. 9 94. 44335 121. Machine 5minute wear, 2() kg.

scar diameter (mm.) 0.389 0. 30s 0. 412 0.299 0. 30s 0. 419 0.386 0.389Weld point (kg.) 170-180 530-540 810 1500-500 400 460-480 420 460-480 Incarrying out our invention it is important to adjust the quantities ofsulfur and haloalkyl phosphite so that the phosphite does not markedlydetract from the antiweld properties of the sulfur and lead naphthenate.We have found that if the proportion of phosphite to sulfur is toolarge, although the-anti-wear properties of the oil are improved, theanti-weld properties are reduced below a satisfactory level so that theoil will not operate satisfactorily as a break-in oil for green gears.The amount of phosphite will depend to some extent on the particularFrom an examination of the table it will be seen that lead naphthenatealone imparts relatively poor loadcarrying and wear-resistant propertiesto the oil as measured by the weld point and scar diameter.Incorporation of 0.1% of sulfur materially increases the loadcarryingproperties as demonstrated by the increase in the weld point, but thewear-resistance of the oil is adversely affected by the incorporation ofthe sulfur. This tendency to detract from wear and to improveloadcarrying properties is further augmented by addition of of 1% oftri(chloroethyl) phosphite to. a blend containing 4% of lead naphthenateand 0.2% of sulfur, the anti-wear property of the oil was materiallyimproved while the load-carrying properties, of the oil remained at ahigh level. Blend No. 5 demonstrates that the ratio of sulfur totri(chloroethyl) phosphite is too low to obtain satisfactoryload-carrying characteristics.

Blendso, 7 and 8 demonstrate that other phosphoruscontaining additiveswere not effective in improving the wear characteristics of the oilwhile at the same time they detracted from the load-carryingcharacteristics of the oil.

The blends included in the table were made from mineral oil having thefollowing characteristics:

Vis./2l0 F. an... 85.3 Vis./130 F. 441 Vis./l F. 1148 V.I v. 74 Pourpt., F. +10 API gravity 23.1 Percent S 1.13

The extract=P S reaction product used in some of the blends was made byreacting at about .22Q- 230 F., for fo r. hours, 1 parts by weight ofphosphorus. pent sulfide and 1 part of' aromatic extract obtained from.the extraction of a neutral fraction with phenol.

The zinc salt of the eXtract=P S reaction product was made byneutralizing the extract=P S reaction product above-described with zincoxide at a temperature of about 250 F. The extract used in making thisproduct had the following characteristics:

Viscosity at 100 F. .SUS 165.5 Gravity APL- 17.3 Flash point Q. F 375aaae e i Fire point F 430 Acid number .-.-:-..-1-a. -8 Sulfur percent2.03

By blending together a haloalkyl phosphite with lead naphthenate andsulfur into a lubricating oil, a product is made which is effective bothas a break-in oil for automotive gears and as a lubricant for use underordinary service so that the break-in oil. does not have to be changedafter the gears are'broken, in but can be left in the transmissionwithout fear of causing excess wear of the gear teeth.

We claim as our invention:

1. A lubricating oil consisting essentially of a mineral Oil of lbricating oi grad a. min r amo n of. lead nap thenate, 0.05-1.0 wt.percent sulfur, 0.255.0 wt. percent of a 0 -0 haloalkyl phosphite, witharatio of phosphite to sulfur in the range of 2 to 5:1, said phosphiteenhancing the antiwear properties of the oil without detractingsubstantially from the an tiweld properties thereof.

2. A lubricating oil in accordance with claim 1 in which the phosphiteis a tri('chlor'oa1kyl) phosphite.

3'. A lubricating oil in accordance with claim 2 in which the phosphiteis tri(chloroethyl) phosphite;

4. A lubricating oil in accordance with claim 1 in which all of thehaloalkyl phosphite present is in solution in the oil. i

References Cited in the file of this patent TED ST ES. T S 2 ,169,185Shoemaker at 1. Aug. 8, 1939 ,1 ,426 Kaufman et a1- .----.---a 0% 7,193.9 2,298,636 Prutton t t- 13, 1942 2,722,517

1. A LUBRICATING OIL CONSISTING ESSENTIALLY OF A MINERAL OIL OFLUBRICATING OIL GRADE, A MINOR AMOUNT OF LEAD NAPHTHENATE, 0.05-1.0 WT.PERCENT SULFUR, 0.25-5.0 WT. PERCENT OF A C1-C30 HALOALKYL PHOSPHITEWITH A RATIO OF PHOSPHITE OF SULFUR IN THE RANGE OF 2 TO 5:1, SAIDPHOSPHITE ENHANCING THE ANTIWEAR PROPERTIES OF THE OIL WITHOUTDETRACTING SUBSTANTIALLY FROM THE ANTI-WELD PROPERTIES THEREOF.